The present invention concerns a device for the detection of rotational parameters, in particular a sensor for detecting the velocity of a vehicle wheel consisting of a toothed ring mounted on a rotating piece (shaft, axle, or hub) in interdependent rotation with the wheel and of a detecting head placed in proximity with the teeth of the ring.
Wheel-velocity sensors are sometimes required on vehicles in order to supply electronic command or control circuits with signals representing the rotational velocity of the wheels, for example, for the purpose of detecting speed variations in order to command an anti-skid system, or in any other application calling upon the velocity of the vehicle and/or its wheels.
Such sensors are generally fitted with, first, a toothed ring rotating with an axle or a wheel of the vehicle and manufactured of magnetic material, and, second, a detecting head placed in proximity with the teeth of the ring; these sensors emit a pulse at the passage of each tooth of the ring and consequently generate signals proportional in frequency to the rotational velocity of the axle or the wheel.